GEPHYREA INERMIA—BENHAM. 15 
Dimensions of P. mawsoni, in which the introvert is fully extended. 
Specimen. 
Total Length. 
Body. 
Introvert. 
Length. 
Diameter. 
Length. 
Diameter. 
A 
mm. 
42 
20 
6 
22 
3 
B 
42 
12 
6 
30 
4 
C 
32 
10 
4 
22 
2 
1) 
29 
13 
4 
16 
1-25 
E 
24 
10 
4-5 
14 
2 
F 
23 
7 
3-5 
16 
2 
Notes. 
In C the hinder end is contracted, so that the terminal cone is surrounded by a fossa, but is visible 
from the side. 
B is more contracted, so that the terminal cone is not visible from the side. 
In E the introvert is curved, but the specimen seems to be more uniformly contracted than the others. 
The hinder end is not at all withdrawn. 
E has the hinder end much contracted. 
The skin is creamy white in colour, opaque and rather rough. The roughness 
is due partly to the circularly disposed but discontinuous wide furrows and narrow 
ridges, and partly to the more or less widely and irregularly scattered papillae, which 
are nearly white (fig. 6). These have the appearance, under a hand lens, of short columns, 
and are especially conspicuous when they are seen in profile. Though widely spaced 
on the body generally, they become more crowded at the hinder end, and also on the 
introvert, where they become more numerous as the tentacles are approached. 
Viewed under the microscope (glycerine preparation), the papillae over the mid¬ 
body are yellower than the surrounding skin; they are skittle-shaped, that is, ovoid 
and slightly constricted at the base (fig. 7). There is no pigment other than the yellowish 
secretion from the gland cells, which latter have a tesselated arrangement. 
The length of a papilla is about one and a third times its breadth. Neither in 
fully extended nor in contracted specimens are any longitudinal furrows or ridges 
visible. 
There are no hooks on the skin. 
Internal anatomy (fig. 11).—The intestine is rather loosely coiled, the upward 
and downward limbs of the coils are not so regularly arranged as in P. margaritaceum. 
I counted twelve double coils in one individual, which was fully extended; while in a 
contracted one of about the same size there are nineteen double coils, and these are 
more regularly disposed, the up and down coils alternating. 
The intestine is free posteriorly, the spindle muscle is very delicate, and I was 
unable to detect its anterior attachment. The anterior coils of the intestine are held 
